Research Interests: Systematics and phylogeny of yeasts through application of gene sequence analysis. Research includes phylogenetic circumscription of species, genera and higher levels of classification, development of a gene sequence based barcode system for rapid identification of species relevant to food spoilage, biocontrol of plant disease, and clinical isolates. Use of phylogeny to predict species of interest to biotechnology. Lead editor of The Yeasts, A Taxonomic Study, 1998, 2010.